carbonate dehydratase activity anhydrase activity carboxyanhydrase activity carbonate hydro-lyase (carbon-dioxide-forming) carbonic acid anhydrase activity carbonic anhydrase activity carbonic dehydratase activity EC:4.2.1.1 GO:0004089 carbonate hydro-lyase activity carbonate anhydrase activity Catalysis of the reaction: H2CO3 = CO2 + H2O. RHEA:10751 MetaCyc:CARBODEHYDRAT-RXN molecular_function carbonic anhydrase A hydro-lyase activity